Flex Fuel Sensor - If Equipped
| ITEM | DESCRIPTION |
|---|---|
| 1 | Electrical connector - Powertrain Control Module (PCM) |
| 2 | Pipe connector - Outlet |
| 3 | Pipe connector - Inlet |
The Flex Fuel Sensor (FFS) is secured to a bracket which is installed in front of the fuel tank. The FFS is located between the High Pressure (HP) fuel pump and the fuel pump module.
The FFS measures the ethanol percentage and fuel temperature of the fluid passing through the FFS. The FFS precisely detects the ethanol proportion at all times. The frequency of the output signal is linearly related to the ethanol percentage of the fuel. The negative pulse width of the output signal is linearly proportional to the temperature of the fuel. The signals from the FFS are sent to the Powertrain Control Module (PCM).
The FFS signal is a square-wave voltage signal. The signal varies in both frequency and pulse width:
- The frequency of the signal indicates the ethanol percentage. The normal range of operating frequency is between 50 Hz and 150 Hz.
- 50 Hz indicates 0 ethanol
- 150 Hz indicates 100% ethanol.
- The pulse width indicates the fuel temperature. The normal pulse width is between 1 ms and 5 ms.
- 1 ms indicates -40°C (-40°F)
- 5 ms indicate 125°C (257°F).